Revealed: Riverhead quarry rapist's previous convictions

The previous conviction for a repeat rapist who committed a violent attack in the Riverhead quarry near Auckland can now be reported for the first time.

The 60-year-old truck driver from Onehunga, Colin Jack Mitchell, was convicted of kidnapping, causing grievous bodily harm and assaulting a woman with intent to sexually violate her in March.

DNA from the quarry scene linked him to a historical rape case that had gone unsolved for 25 years. The jury found him guilty of that attack as well.

But what the jury did not know was that Mitchell had raped before.

The case had remained the subject of a suppression order until today. RNZ challenged the order in the Court of Appeal and the senior court revoked the order today.

At the age of just 15, Mitchell raped a woman in her flat. He was sentenced to five-and-a-half years in Mt Eden Prison.

The woman who he raped told RNZ that being in court and watching Mitchell as he was convicted for the quarry attack and another rape - his fourth - was liberating.

"I was there to honour the women - I was there 100 percent for [the victim of the quarry attack]. It was not only to honour my experience but to hear these women who were giving evidence."

She recalled giving evidence at Mitchell's first trial, over 40 years ago.

"It's an incredibly invasive process, to stand up there and transport yourself back - to go second by second through it. To be led into places on your body that are yours alone but all of a sudden you're talking to the jurors - and the media and everyone's listening."

The verdict of guilty was just the beginning for her recovery and she said she felt empty afterwards.

She said later she wrote a letter to Mitchell, asking to meet him but he refused.

"I didn't want him to say sorry. I just wanted him to see a really strong woman."

She is determined that the experience of being raped and going through the justice system does not define her.

"I've transitioned through being a victim, being a survivor. I'm me. I'm not defined by what happened."

The woman also paid tribute to her husband who has always stood by her and was also in court when Mitchell's latest guilty verdicts were handed down.

She's also proud of Mitchell's other survivors, particularly the 23-year-old woman who was abducted from Great North Road and driven 25km to the Riverhead quarry.

Asked what needs to change, the woman told RNZ, the country needed to look to the next generation and breed more "warrior women".

"And bringing up sons who are respectful in a way they conduct relationships with women."

She said it was also important to remember that there are a lot of men who have been damaged in their childhood years but do not go on to rape.

At his sentencing at the High Court in Auckland (then referred to as the Supreme Court) in 1973, Justice Henry said he would have sentenced Mitchell to preventive detention - a life sentence that would mean he would only be released once he could prove he was no longer a threat to society.

"You are only 15 years, and, of course do not qualify for that, and unfortunately also, so far as I know, there is no suitable institution to which you may be sent, and therefore you will pose a special problem, as I see it, for the Secretary of Justice …"

He said the court had to arrive at a "proper sentence to protect women folk, in particular, from this unfortunate aberration from which you suffer".

The judge said he hoped Mitchell got all the psychiatric help possible.

Mitchell went on to rape again.

One of his victims was a young prostitute who Mitchell picked up on Upper Queen Street, and drove to the railway yards in Mt Eden.

He raped and sodomised her before threatening her that if she ever told of what happened, ten of his friends would find her and do even worse.

That was in 1985. Mitchell was sentenced to a further five years in prison.

Shortly after getting out of prison Mitchell raped again but this time the crime went unsolved for 25 years.

It was only tied to Mitchell when DNA from a glove he left at the scene of the quarry attack matched the DNA of an unsolved rape in 1992.

The woman had just been to a gig at Ponsonby's iconic Glue Pot Cafe and was walking home when she was offered a lift by Mitchell.

He dropped her at an industrial area, telling her he worked nearby and then drove off.

A short while down the road a man jumped out from behind a tree and punched her in the head and face before putting her in a headlock and pulling her down a driveway to a spot behind a factory.

The woman told Mitchell's trial earlier this year that she bit him on the hand and was punched again. She told the court she thought she was going to die.

"I was terrified. I was wondering if I was going to get home or not. I was wondering if that was the day I was going to die. I was thinking about my children … I was talking about my children."

She said Mitchell demanded she kneel down and take her clothes off. He used her clothes to cover her face and then raped her.

"My mind was taking a little bit of a holiday. I was in shock. I couldn't believe this was happening to me."

She told the court she was "babbling" and tried to strike an emotional chord with her attacker in the hope he wouldn't kill her.

She told him "don't hurt me, I want to go home to see my children. I started babbling a lot about my children. He asked me how old they were."

She said he apologised before ransacking her bag, tying her up, gagging her and telling her to stay still for 20 minutes.

He threatened her, saying he knew his way around Avondale and she'd end up in a dumpster if she didn't do what he said. Then he left.

The woman said she got free from her ties, got dressed and rolled a cigarette.

"I was grateful for being alive but I was really scared, really scared that I might make a noise and he might come back."

She walked down the middle of the road before seeing a payphone and calling the police.

But the police didn't believe her. Their investigation was compromised from the beginning when they sent a male security guard to the scene - not detectives.

She was kept awake for the rest of the night, went through a medical exam and made a formal statement later that morning.

The woman said she felt stupid for having got into a car with a strange man, and because of her treatment by the police, she told them she had been picked up by a woman.

She said she felt like the police officers didn't believe she had been raped.

"I think I was pretty shell-shocked actually, the whole process was pretty revolting. It was just a bit too much."

Later she said: "They [the police] weren't very nice. They were treating me like a criminal, like I deserved it."

Under cross-examination at trial, Mitchell's lawyer Mark Ryan put it to the woman that she had met Mitchell at the Glue Pot and the sex was consensual. She replied: "Hell, no."

Under re-examination from Crown prosecutor Kirsten Lummis, the woman said when police officers approached her last year to tell her they had arrested the man who raped her, the experience was completely different.

"It was nice. It was relaxed. It was easy. I didn't feel like... I felt like a person on the right side of the law... [previously] I felt like I had done something wrong and was being brought in for questioning."

When asked by Ms Lummis how she felt when asked by Mr Ryan if she was making up her story, the woman responded "like I was back in 1992".

That rape went unsolved.

Fast-forward 25 years to the night of 26 February last year. Colin Jack Mitchell was driving through town late at night.

The gay pride festival had just finished.

In his car Mitchell had gloves, a mask and a pool cue. He found a young drunk woman walking by herself. Mitchell got her into his car and drove her to a quarry in Riverhead, north-west of Auckland.

She told the police her first memory of the incident was coming around to find she had blood on the side of her head.

Her dress was off and she could not recall how this had happened. She was lying on her side on gravel.

The woman said there was a man standing over her - it was dark but there was a light coming from behind him and she could see he was wearing a white face mask and holding a bat.

She said the man sounded strange as he began issuing demands that sounded almost robotic.

She begged him not to hurt her and told him he did not have to be this person. He made some kind of threat, telling her that she was going to get herself killed or something similar.

The woman told the police she knew what he wanted to do, but said she would rather die than let that happen.

The man then hit her in the head with the bat.

The woman described it as feeling like a burn and she believed she blacked out.

The next thing she knew, she was scrambling up a pile of gravel while on the phone to police.

The woman said she did not know where she was but followed a fenceline. She also did not know where her attacker was.

Eventually she found a building and a street sign and she was able to direct the police to where she was.

Investigators were quick to link Mitchell's car caught on security camera footage leaving the quarry at speed. Detectives didn't have a number plate but they did have what was thought to be a mobility sticker on the windscreen that narrowed the field of owners of that type of car. There was a similar car caught on security cameras cruising inner city streets, shortly before the woman was taken.

They also found a glove at the scene.

When investigators visited Mitchell's Onehunga flat, they took a toothbrush. The DNA was a match and put Mitchell at the quarry scene.

At his sentencing, Justice Fitzgerald had this to say:

"In my view, there is a clear and disturbing pattern of serious sexual offending by you, over a period of some decades. Having considered your full offending history, there is also a clear similarity between the nature of your offending, including its predatory nature, offending against strangers, seeking out vulnerable victims, associated violence, threats of further violence if instructions are not carried out, and in more recent times, removal of your victims to remote locations to prevent detection."

The 60-year-old has been sentenced to preventive detention with a minimum non-parole period of 10 years. The sentence means he cannot be released until he proves he is no longer a threat to society.

Mitchell has bladder cancer and continues to deny his offending. His refusal to take responsibility means he will not be able to take part in rehabilitation courses while inside prison - making him an unlikely candidate for parole.